Birmingham City's Trevor Francis poses for the camera in March 1971 aged just 16, having scored 11 goals in his last six matches. Photograph: Popperfoto

1) Trevor Francis

Probably the best way to gauge the way Trevor Francis introduced himself to English football is to go back to those early days and the headlines on the BBC's Sports Report one night. "And Trevor Francis did not score today!" came the announcement during his first season at Birmingham City. The date was February 1970. Francis was two months short of his 17th birthday.

By any standards, his induction into the Football League had been phenomenal. Francis scored 15 goals in his first 15 matches. He was fast, brave and he could score goals from any angle and any distance. "St Francis of St Andrew's", as the newspapers tagged him, or simply "Super Boy", bagged four in one afternoon against Bolton Wanderers. Many years later, I asked him about that game and his abiding memory was not actually scoring but having to come off injured. His replacement had missed a good chance to make it five – and Francis said, very matter-of-factly, that he would have scored it.

The following day he was back with the apprentices sweeping the terraces and cleaning the other players' boots. "There was no way I could possibly believe the wonderboy tag."

The sad thing about modern-day football is that a club of Birmingham's size would have almost no chance these days of hanging on to a player who was banging in goals with so much panache.

Back then, Francis lasted almost 10 years at St Andrew's before Nottingham Forest made him the first-ever £1m footballer – or £999,999, to be pedantic – and the pinnacle of his brilliant yet ultimately injury-affected career, on a balmy night in Munich's Olympiastadion, when Francis ended up on the shot-putters' circle, having just headed in the winner in a European Cup final.

Brian Clough would later describe him as "a disgrace to his profession at Birmingham." Yet try telling the Brummie fans that. Rob Hughes, in his 1980 book Trevor Francis, Anatomy of a £1m Player, remembers there being a "Francis cult" at St Andrew's.

In his first two seasons, with the club in the old Second Division, the teenager's emergence can be directly linked to why Birmingham's crowds swelled to nearly 50,000. In 1972, after winning promotion, 52,104 people shoehorned into St Andrew's for one game. When Francis left seven years later, and Birmingham's decline set in, the gates were a quarter of that amount.

Francis also belonged to a time that nostalgia can make feel that little bit more innocent. His father, Roy, a shift foreman with the South West Gas Board, would make the seven-hour drive from Plymouth (before the days of the M5) to every game at St Andrew's. His mother, Phyllis, raised petrol money by sewing and tailoring, at six shillings an hour. From the age of 15 to 17, the scorer of 800-plus goals in Devon schools football lived in three lots of digs. As a 16-year-old tipped for England stardom and described by his manager, Freddie Goodwin, as "the best prospect since George Best", he was operating to a 10.30pm curfew and had to get written permission before he was allowed to see in the new year.

"You looked at Trevor and saw everything you want as a footballer," Goodwin said very early on. "If a manager is lucky, he comes across a youngster like this once in his career. Looking for comparisons, I'd say Jimmy Greaves, Denis Law and that's it. Francis is in this exclusive scorer's bracket." DT

2) Martina Hingis

Tennis is not short of prodigious talent: making her professional debut at around the same time as Hingis, late on in 1994, was another 14-year-old, Venus Williams – who, in case you had to google "tennis" at the start of this sentence, went on to have quite the career, winning seven grand slam singles titles to Hingis's five. By 1994, of course, Jennifer Capriati had already had time to win the US and French Open junior singles titles (aged 13), an Olympic gold medal (three years later), and get arrested for shoplifting and possession of marijuana. By that token she was, as the Chicago Sun-Times put it, "the poster child for burned-out sports prodigies".

Though one of Hingis's retirements followed a positive test for cocaine at the age of 27, she cannot challenge Capriati for that title. No, the "Swiss Miss", to use a title seemingly invented with the sole intention of exercising our gag reflexes, was simply an outstanding junior. She was the youngest ever winner of a junior slam title when, at 12, she won the French Open. Twelve years old! And by then she had been playing tournament tennis for eight years. At the age of 13, she held on to the French title and added Wimbledon, becoming in the process SW19's youngest junior champion. Bored on the junior tour, she turned professional just after her 14th birthday – and just before the rule change that would have kept her off the women's tour until 15.

With Capriati's mugshot all over the newsstands, the reaction was cautious with more than a dash of foreboding. "If she is good at 13, she will be good at 18," said her namesake Martina Navratilova, scared as much by the potential for catastrophe as she was impressed by the solidity of Hingis's game. She was small but she was smart, able to play from the front and back of the court and work players who could overpower her given time to catch their breath. By the time she had her first crack at the senior French Open, aged 14, she was inspiring breathy prose. "Hingis floats above the ground almost," wrote Diane Pucin, then with the Philly Inquirer. "She is so light, and when the rain made the clay mushy and thick, Hingis couldn't tell the difference." Hingis reached the third round before losing to Lindsay Davenport.

Under the new rules she would have been kept out of grand slam competitions until the age of 16 – as it was, she was restricted to 12 tournaments a year until then. "I wish I could play more," she said. Part of that was her then unshakable self-belief: already she would look at the draw for a tournament and see a path through it (she once said to Davenport, a player she always admired, during a coin toss: "Do you want me to serve, or break you?" Later her willingness to comment on her opponents would get her into trouble). But she had the game to back it up: at 15, she became the youngest ever grand slam champion by winning the Wimbledon doubles title with Helena Sukova.

The best that most of us can hope for from the year we turn 16 is a decent set of exam results and a dinner out at TGI Fridays (milkshakes allowed). Hingis, meanwhile, competed in all four grand slam singles finals, winning three of them – only the French slipped messily from her grasp, an improbable defeat to Iva Majoli. When Hingis had lost to Mary Pierce in her first professional tournament just over two years earlier, reporters made the most of their differing statures. "Martina Hingis found out how the big girls play," said the Daily Mail. "Hingis's time will come when she grows a little and adds an adult serve to an already impressive armoury." In the final of the 97 Australian Open, Hingis beat Pierce in what the Times described as "an hour of withering tennis" with a 6-2, 6-2 scoreline. She also won the doubles title, this time with Natasha Zvereva. "[Hingis has] matured from a little girl into a young woman," said the Times. "A lot of women are going to feel middle-aged." That included the 17-year-old Venus Williams, swatted aside in that year's US Open final.

Although she retained the Australian Open title for the next two years, and in 1998 held all four grand slam doubles titles, Hingis was never more frightening than she was at 16: a precocious talent with a game so full of assets that it was hard to appreciate them all in the same glance. GT

3) Beverly Klass

Think about what you did as a 10-year-old. Beverly Klass was playing on the LPGA Tour. "It was my father's decision," she later ruefully recalled. "I didn't even know there was a pro Tour. But it didn't faze me one way or another." By now – driven on by father Jack (more of whom later) – Klass had been playing for six years, could drive the ball a reported 223 yards and had won around 25 junior tournaments, among them the 1964 National Pee Wee Championship … by 65 strokes. So it was that this pint-sized tyro from California, all 4ft 10in of her, stepped on to the tee at the 1965 Dallas Civitan Open. She carded two 88s.

Klass played in three more tournaments, making a solitary cut and earning $135, before the LPGA put its foot down, refusing to accept her entry fee at the next event on account of child labour laws and imposing a minimum age of 18. The Klass Clause. Undeterred, Klass waited, winning 25 amateur events, all the while enduring a volatile relationship with her father, one that even forced her to run away from home. "He'd yell and scream and corner me in the bathroom with a belt," Klass told USA Today in 2003. "He hit me until my back was bleeding. He cursed at me from the sidelines at tournaments." When she turned 18, Klass caught the Greyhound to Florida and embarked on a 13-year Tour career, collecting $234,330 in the process. "Child prodigies develop talent but they don't develop relationships," Klass would later say. "And my talent was a blessing that became a burden. I suppose my parents did the best they could but it didn't turn out great. There were more times of horror than good times." JD

4) Joy Foster

By the age of eight, Joy Foster had three Jamaican national titles under her belt and a place in the Guinness record book as the world's youngest champion. Yet her feats in 1958 are little remembered outside of the Caribbean. However, those three 1958 titles were just a handful of the trophies she would go on to win – even aged eight, the Jamaica Gleaner photographed her stood by a trophy cabinet groaning under the weight of the 20 pewter cups it held, the caption reporting that she had more trophies than anyone else on the island.

Chubby-cheeked and innocent-faced, she played with her hair in ponytails and ribbons. She would beat adults more than twice her age and go on to win the Caribbean women's single titles twice before she was 12, compete in the United States and be named Jamaica's first sportswoman of the year at 11 years of age.

And then, in her teens, she turned away from the sport that had made her famous having already peaked. From there, she slipped away from the spotlight – at least outside Jamaica. Perhaps she would have been more heralded around the globe if she hadn't – but then again the sport in which she excelled has never had the same cachet as the footballs and crickets of the world. But, for a few years at least, Joy Foster was the greatest child to have ever picked up a table-tennis bat. TB

5) Mike Tyson

The youngest ever heavyweight champion at 20 years, four months and 21 days; the undisputed champion of the world just 19 months later – Mike Tyson may seem old compared to some of the names listed here, but in a sport where world champions are commonly in their 30s his prodigy pedigree cannot be doubted.

Initially written off as too short for a heavyweight at 1.78m (5ft 10in) – Tyson enjoyed proving his doubters wrong, rising from his deprived Brooklyn childhood to dominate the boxing scene. Pointed in the direction of renowned trainer Cus D'Amato by a juvenile detention centre worker, D'Amato channelled the 13-year-old's demons and moulded the boxer he was to become. Tyson's compact frame suited the Peek-A-Boo style developed by his tutor, and he earned his first shot at a belt in 1986 against Trevor Berbick – 13 years his senior. It didn't last long – the referee put a halt to proceedings at the start of the second round when Tyson connected with a sweet left-hook. Berbick tumbled to the canvas and then staggered around the ring like a drunk uncle at a wedding, falling over twice more before regaining some semblance of composure. And so a boxing superstar was born.

Of course, Tyson has since followed a path familiar to so many who enjoy success so young – who knows what may have been had his mentor D'Amato not died when Tyson was only 19. It's both ugly and tragic that, for many, one of the world's great fighters will be better remembered for rape, bitten ears and the terrible Hangover movies than the epic battles fought within the ring. TM

In the internet age, nobody is a secret any more. If you think you've heard of him first, or him or even him, you're wrong, someone else already got there last week and it's already gone viral. Which is precisely what happened when young Hachim Mastour burst on to the scene last year, alerting the world to his awesome potential when he was caught on camera playing for Milan's youth team and becoming an overnight YouTube sensation, nicknamed the Moroccan Messi. A performance of amazing tricks, dinky flicks, defence-splitting passes and an outrageously impudent goal led to his anointment as the Chosen One. Milan even appealed to Serie A for special permission to include Mastour in their squad, even though he's under-age. And there's the rub: he's only 15. Mastour is not the first Mastour. He may make it but there have been many like him who have been unable to handle the expectation on them, the Freddy Adus of this world. But let's hope he doesn't go down that route. The boy does look special. JS